A novel use of a prepared membrane from extracted chitosan in the electro-generation of ferrate (VI) in a double compartment cell

Abstract

The main challenge of the electro-generation of ferrate (VI) is the low yield and the instability of the obtained ferrate (VI). In this work, we concentrated on improving ferrate stability and enhancing the synthesis yield at a lower cost. The electrochemical synthesis of ferrate is carried out using a two-compartment electrochemical cell divided for the first time with a chitosan cation exchange membrane prepared from extracted chitosan as a green non-toxic biopolymer. The elaborated chitosan membrane was first characterized using FTIR (Fourier-transform infrared spectroscopy), XRD (X-ray diffraction), and TGA–DSC (thermogravimetric analysis and differential scanning calorimetry) analysis. Different vital parameters influencing the performance of the synthesis were optimized. The FTIR spectra of the chitosan membrane show characteristic peaks at 1573 and 1640 cm⁻¹. The XRD results indicate a semi-crystalline structure of chitosan, while the TGA–DSC shows a high thermal resistance. The ferrate synthesis results show that 210 min of electrolyze is optimal for ferrates (VI) synthesis at 30 °C, under 60 mA/cm², in a NaOH (sodium hydroxide) electrolyte of 24 M for a maximum concentration of 0.19 M. The resulting product was characterized quantitatively and qualitatively using UV–Vis (ultraviolet–visible spectroscopy), XRD, FTIR, SEM (scanning electron microscopy), TGA, and chromite titration. The UV–Vis results show a characteristic peak at 504.5 nm, the XRD pattern confirms an orthorhombic structure, and the FTIR spectra show a distinct peak of 865 cm⁻¹. The high concentration of Ferrate of 0.19 M shows the efficiency of the membrane used. 

Graphical Abstract